AS WITH ALL MODS, YOU ARE DOING THIS AT YOUR OWN RISK AND I AM NOT CLAIMING RESPONSIBILITY FOR ANY DAMAGE (TO YOU, YOUR PROPERTY, OR OTHERS) THAT OCCURS DUE TO THIS!!

I did this mod in a hybrid, so it will be a little different, especially the rear seat part. The trunk part should be pretty much the same though.

Okay. Here are some pics of what I did:
I removed all of the trunk lining and the spare tire.
I covered the whole spare tire compartment in foam.
I also covered the wheel wells with one layer, then stuffed the extra space above them with more foam. I covered the space between the trunk and the rear firewall that was not being insulated by the battery. (did that on both sides, only one is pictured)
BE SURE TO LEAVE PLENTY OF ROOM FOR VENTILATION OF THE BATTERY!!!
Personally, I just made sure there was room between the battery exhaust and the flaps that let the exhaust out of the trunk. If not properly installed, it is possible that this insulation can cause your battery to heat up and have it's life lowered (and possibly void the warranty)! Be careful!

Next I took off the back seat. It is very easy to do.
1. Unscrew the 10mm bolt between the rear right (when sitting in driver seat) seat and the rear center seat. It is between the seat cushion and the seatback, where the two seatbelt buckles come out.
2. Now that you have removed the only screw holding the bottom cushion in, pull up on the front, to release two clips (each under the side passenger seats). The entire seat bottom comes out quite easily.
3. To remove the back, there are two 10mm screws on either far side of the seat back (on the bottom, parallel to the first). There is also 1 10mm screw towards the center of the seatback (parallel to the other two)
4. Now the hardest part... Once you have removed all of the screws, the seatback is ready to come out. Move all the seatbelts around the sides of the seatback, so it can come out. Lift up, with quite a bit of force. The seat should release. Pull back on the seat and it will come out.
Note: I did this by myself, but it would definetley help to have two or three people. Please be careful when doing this!!!
Please be careful not to:
1. Hurt your back trying to release the seatback.
2. Scratch yourself of the car with the sharp metal parts on the seat.
3. Mess with the battery or any IMA components while they are exposed. (they are not really exposed, but if you do have access to them w/o the seat removed)
Please remember to install the seat correctly, otherwise you are posing a danger to you and your passengers.

I forgot to take pics of this, but you can see where that the seat screws into the rear wheel wells. I covered them in foam and it greatly reduced the noise.

While you have your seat off...
Lift up the interior trim on either side of the rear seat (next to the door). (be careful not to break any clips) This will allow you to peel up the carpet and slide some foam under the rear floor. This is what size I used:
I put it under the carpet, but I just put it on top to show the size.

Everything goes back on in the reverse order you installed it. Once all the covers are on in the trunk, the only way to see the sound deadening is to lift up the spare tire cover. It is not visible/noticeable at ALL in the interior cabin. (except for the fact that it's much quieter )

For about $30, this is definitely worth it. I will post more pics if/when I get to the front of the car.

How much did the sound deadening help? My hybrid is rather quiet compared to some of my previous cars, but silence is always welcome. Did you consider any of the Dynamat or other brand name sound deadening materials at all.

(haha I just replied to your post at GH)
I was looking at Dynamat, but it was pretty expensive. The HCH is pretty quite as far as the engine goes, but the freeway in my area is undergoing construction, and this helps a lot. It was only $29 and the car is noticeably quieter. I noticed that I would always just turn up my radio when I went on the freeway. Try turning your radio off for a while, I was surprised at how loud it was. If you don't think it's too loud, you can always spend the $29 on something else for your car.

What type of foam did you use and where did you get it? It looks like carpet padding, but would like to know if it is something special. Did I read that you are going to do the front of the car as well? If so, I am very interested in the outcome as well.

you should try using some industrial grade aluminum foil to cover the foam, it will further dampen it, just use some foam spray mount, then maybe spray mount the foam directly onto whatever surface so it takes the shape and also dampens out any rattles too. and use some aluminum tape for the seams. I've used the foil method with neoprene foam sheets before and works great, i might do i double layerd pad.

great post! I'll be trying out your ideas with a few modifications gere and there soon, i'll post some pics soon.

i did the same thing to mine too. except i did the front part where the driver and passenger foot are. i completely noticed a sound deadening difference. i believe i used the exact same carpet underlay. i just never did the rear area. this is a good idea, i was thinking of using dynamat over the rear wheel wells. maybe this summer ill use dynamat, and maybe that firewall material they use. i was thinking of using that firewall material and 3M glue it to neoprene i might get a decent sound absorber to line those parts.

I just got back from Home hardware. I bought 2 cans of 3M Spray adhesive for foam ($10 each), Two Rolls of Aluminum Tape ($5 each) and 9 square meters of Foam Carpet insulator (identical to above for $25). I also bought 5 cans of rubberized spray coating (for sound insulation and rust prevention) from Canadian Tire for $3 each (on sale hehe). I am going to Rempve all the interior, then Cover all of the Critical Areas where I want sound dampened with Carpet insulator attached with 3m adhesive, and then coat any suspicious areas or areas that are possible exposed with moisture with the rubberized coating, this includes removing all the plastics from wheel wells and coating them in 2 layers of this good suff (weather proof, does not crack = good stuff) As I do this I will talke lots of pics and make a pretty simle (lenghty DIY)

Thanks for the idea, I have been looking for ideas for a project like this.

Register Now

In order to be able to post messages on the 8th Generation Honda Civic Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

Log-in

User Name

Remember Me?

Password

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.

AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.